Here's is what I am doing with these...

I record the numbers for a horse that I find most important to me in a spreadsheet program (Open Office). Using a simple function in Open Office I easily add the totals for a horse and get a final number. I went through all my transfer pool horses (138 horses) and did their numbers. With the average function I came up with an average number for each of the categories. I color coded green any number that is above the average for a category. In the totals column I color coded purple the horses who are in the very upper percent numbers wise.
The first 4 categories POT,EXTRA,CRUIS and FIN are far and away most important to me. In order of importance to me also.
The next 3 ACCEL,SPEED and START are from the main parameters box. In order of importance to me.
The next 6 BATT,ENTH,CONF,CONSISTENCY,GOINGADAPT and DIS.ADAPT are secondary stats bars that I think are somewhat important. In order of importance
The first 3 totals columns are the totals from the each of the above categories and the last total is these 3 combined.
In the above examples Maddy's total of 963 is easily the best. But it's mostly boosted by her secondary stats total. Her potential is crummy and her parameters total is bad. She wasn't a superstar in game or the CK. But I hope to pass on her secondary stats to others. Space Journey is the last horse to hit the transfer pool. His numbers surprised me. Chac Du Cadran was one of 3 with the highest parameters total. A gamebred.